Kazakhstan has marked the death of 14 soldiers and a hunter in a mysterious
fire at a remote border outpost with a day of official mourning.

The charred remains of the soldiers were discovered on May 30 in the wreck of their base near the border with China.

After a five day manhunt, news agencies reported that on Monday the security forces had found and detained the outpost's one surviving soldier. His evidence will be vital in solving the mystery.

Over the weekend, Kazakh President Nursultan Nazarbayev called the incident an act of terrorism, although it wasn't clear who would carry out such an attack, and the authorities declared Tuesday an official day of mourning.

Last year, Islamic extremists launched a series of fairly crude bombs in cities around Kazakhstan but there have been no attacks in 2012 and nobody has claimed responsibility for an attack on the outpost.

Media reported that the outpost is a temporary one, established only during the summer months to stop Chinese crossing the border to pick wild plants for medicines.

Aside from terrorism, other theories have focused on the fire being an accident or a so-called hazing episode that turned into a tragedy.

Hazing is the term used to describe the bullying of young recruits in the armies of the former Soviet Union.

Media, though, have cast doubt on the fire being an accident as they quoted officials as saying that the soldiers had been killed before the fire. The hunter was reportedly found shot dead in a nearby hut.